JPH01144438A - Sealing resin composition - Google Patents

Abstract

PURPOSE:To obtain the title composition, containing an epoxy resin, novolak type phenolic resin, a specific amount of fluorine-substituted alkylalkoxysilane compound and a specified amount of an inorganic filler, having excellent moisture, solder heat resistance and moldability and useful as electronic.electrical parts, etc. CONSTITUTION:The aimed composition containing (A) an epoxy resin, (B) novolak type phenolic resin, (C) 0.1-5wt.% fluorine-substituted alkylalkoxysilane (e.g., a compound expressed by the formula) and (D) 25-90wt.% inorganic filler (preferably silica or alumina) as essential components. Furthermore, the equivalent ratio (alpha/beta) of the epoxy groups (M) in the component (A) to the phenolic OH groups (beta) in the component (B) is preferably within the range of 0.1-10.

Description

DETAILED DESCRIPTION OF THE INVENTION [Purpose of the Invention (Industrial Application Field) The present invention relates to a resin composition for sealing electronic/electrical parts, etc., which has excellent moisture resistance, soldering heat resistance, and moldability.

(Prior Art) In recent years, along with technological developments for higher integration and higher reliability in the field of semiconductors and integrated circuits, automation of semiconductor device mounting processes has been promoted. For example, when attaching a flat package type semiconductor device to a circuit board, conventionally soldering was done for each lead bin, but recently the entire semiconductor device is immersed in a solder bath heated to 250 degrees Celsius and soldered at - A method of attaching is used.

A semiconductor device sealed with a conventional resin composition comprising an epoxy resin, a novolac type phenol resin, and an inorganic filler has a drawback that moisture resistance is reduced when the entire device is immersed in a solder bath. In particular, when a semiconductor device that has absorbed moisture is immersed in a solder bath, peeling occurs between the sealing resin and the semiconductor chip and frame, resulting in significant deterioration of moisture resistance, disconnection due to electrode corrosion, leakage current due to moisture, and long-term The drawback is that reliability cannot be guaranteed. For this reason, there has been a strong demand for the development of a sealing resin with good moldability that has less influence on moisture resistance and exhibits less deterioration in moisture resistance even when the entire semiconductor device is immersed in a solder bath.

(Problems to be Solved by the Invention) The present invention has been made to eliminate the above-mentioned drawbacks and meet the demands. The object is to provide a encapsulating resin composition that is crushed and has good moldability.

[Structure of the Invention] (Means for Solving the Problems) As a result of extensive research to achieve the above object, the present inventor has developed a resin composition containing a fluorine-substituted alkyl alkoxysilane compound that can be used in solder baths. The present invention was completed based on the discovery that the moisture resistance and soldering heat resistance after immersion are improved, and the moldability is improved. That is,
The present invention comprises <A) an epoxy resin, (B) a novolac type phenol resin, (C) a fluorine-substituted alkyl alkoxysilane compound, and (D) an inorganic filler as essential components, and the above-mentioned ( C
) of the fluorine-substituted alkyl alkoxysilane compound.
1 to 5% by weight, and 25 to 5% by weight of the inorganic filler <D) above.
This is a sealing resin composition characterized in that it contains 90% by weight. Then, the equivalent ratio of the epoxy group (a> and the phenolic hydroxyl group (b) [(a)/(b) is 0
．． It is a sealing resin composition within the range of 1 to 10.

As long as the epoxy resin used in the present invention (A> is a compound having at least two epoxy groups in its molecule, there are no particular restrictions on its molecular structure or molecular weight, and epoxy resins that are generally used as sealing materials may be used. Examples include aromatic resins such as bisphenol, alicyclic resins such as cyclohexane derivatives, and epoxy novolac resins represented by the following general formula.

(tE! L, in the formula, R1 represents a hydrogen atom, a halogen atom, or an alkyl group, R2 represents a hydrogen atom or an alkyl group, and n represents an integer of 1 or more.) These epoxy resins can be used alone or as a mixture of two or more types. and use it.

The (B) novolak type phenolic resin used in the present invention includes novolak type phenol resins obtained by reacting phenols such as phenol and alkyphenol with formaldehyde or paraformaldehyde, and modified resins of these, such as epoxidized or butyl Examples include chemical novolac type phenol resins, and these resins may be used alone or in combination of two or more. The blending ratio of the novolac type phenolic resin is determined by the equivalent ratio [<a)/
(b) It is desirable that the ratio be within the range of 0.1 to 10. If the equivalence ratio is less than 0.1 or exceeds 10, the moisture resistance, molding workability, and electrical properties of the cured product will deteriorate, and any Therefore, it is better to limit it within the above range.

Examples of the (C) fluorine-substituted alkyl alkoxysilane compound used in the present invention include CF, CH2CH2Si (QC2H)3, CHF
2CH2CH25t (OCH, >3, CHF20F
Examples include 2CH2CH2Si(QC2H5)3, which may be used alone or as a mixture of two or more.
The blending ratio of the fluorine-lit alkyl alkoxysilane compound is 0.1 to 5% by weight based on the entire resin composition. If the proportion is less than 0.1% by weight, it has no effect on soldering heat resistance, and if it exceeds 5% by weight, it has an adverse effect on moldability such as a decrease in resin viscosity, making it unsuitable for practical use.

Examples of the inorganic filler (D) used in the present invention include silica powder, alumina, antimony dioxide, talc, calcium carbonate, titanium white, clay, mica, red iron, glass fiber, etc. Mix and use.

Among these, silica powder and alumina powder are particularly preferred and often used. The blending ratio of the inorganic filler is 25 to 90% by weight based on the entire resin composition. If the proportion is less than 25% by weight, the moisture resistance, solder heat resistance, mechanical properties and moldability will be poor, and if it exceeds 90% by weight, the coverage will be large and the moldability will be poor, making it unsuitable for practical use.

The encapsulating resin composition of the present invention contains an epoxy resin, a novolac type phenolic resin, a fluorine-substituted alkyl alkoxysilane compound, and an inorganic filler as essential components, but may optionally contain natural Waxes 1 Synthetic waxes, metal salts of linear fatty acids, acid amides, esters, release agents such as paraffins, chlorinated paraffins, brominated toluene, hexabromobenzene.

Flame retardants such as antimony trioxide, colorants such as carbon black and red iron oxide, silane coupling agents, various curing accelerators, etc. can be appropriately added and blended.

A general method for producing the encapsulating resin composition of the present invention as a molding material is to mix an epoxy resin, a novolac type phenol resin, a fluorine-substituted alkyl alkoxysilane compound, an inorganic filler, and other raw materials into a predetermined composition. After sufficiently uniformly mixing using a mixer or the like, the mixture is further melt-mixed using hot rolls or mixed using a kneader, etc., and then cooled and solidified, and pulverized to an appropriate size to form a molding material. The molding material thus produced can be applied to sealing, covering, insulating, etc. electronic or electrical components.

(Function) In the present invention, the desired characteristics can be obtained by using a fluorine-substituted alkyl alkoxysilane compound. The fluorine-substituted alkyl alkoxysilane compound improves the adhesion between the encapsulating resin composition and the semiconductor chip,
Furthermore, it is possible to improve the adhesion between the sealing resin composition and the lead frame, and to reduce deterioration of moisture resistance even when immersed in a solder bath.

(Examples) Next, the present invention will be specifically explained by examples, but the present invention is not limited by these examples.

In the following Examples and Comparative Examples, "%" means "% by weight".

Example 1 Cresol novolak epoxy resin (i 2 per epoxy
15) 19% contains novolak-type phenol IfA fat (
Phenol equivalent 107) 9%, CF3CH2CH2Si (QC2H5
), 0.3%, fused silica powder 7
1%, ester wax 0.3% and silane coupling agent 0.4%, mixed at room temperature and further heated to 90~
After cross-cooling at 95° C., the mixture was pulverized to produce a molding material. This molding material was transfer-injected into a mold heated to 170°C and cured to produce a molded product (sealed product).The molded product was tested for characteristics such as moisture resistance, and the results are shown in Table 1. It was shown to. In particular, the remarkable effects of the present invention on moisture resistance were observed.

Example 2 Cresol novolac epoxy resin (epoxy equivalent weight 21
5) 19%, 9% of novolak type phenol resin (phenol equivalent: 107), 0.3% of the following fluorine-substituted alkyl alkoxysilane compound, Example 2, CHF2 CH2CH281 (OCHx )
s, Example 3 is CHF2 CH2CH2Sf (QC2H5
)! , 71% silica powder, 0.3% ester wax and silane turnip, 0.4% pulling agent.
were mixed, mixed, and crushed in the same manner as in Example 1 to produce a molding material.

In addition, molded products were made in the same manner as in Example 1, and property tests such as moisture resistance were conducted, and the results are shown in Table 1. The remarkable effect of the present invention on moisture resistance was observed.

Comparative Example Cresol novolac epoxy resin (i 2 per epoxy
15) Example: 19%, 9% novolac type phenol resin (phenol J1107), 71% silica powder, 0.3% curing accelerator, 0.3% ester wax and 0.4% silane coupling agent. A molding material was produced in the same manner as in Example 1. This molding material was used to make a molded article, and the properties of the molded article were tested in the same manner as in Example 1. The results are shown in Table 1.

Table 1 (Units) *1 A molded product with a diameter of 50 m1 and a thickness of 31111 cm was made by Nidor Transfer molding and heated to 127°C.

It was determined by the increase in weight after being left in saturated steam at 2 atm for 24 hours.

Ne2: Make the same molded product as in the water absorption test, and test this with 17
Post-curing was performed at 5° C. for 8 hours, a test piece of an appropriate size was prepared, and the test piece was measured using a thermal instrument analyzer.

*3: Using a molding material, a silicon chip (test element) with two or more aluminum wirings is
70 frame and transfer molded at 175° C. for 2 minutes to produce a flat package molded product of 5 x 10 x 1.5 nIl, followed by post-curing at 175° C. for 8 hours. This molded product is heated to 40℃ and 90%
After RH and moisture absorption treatment for 100 hours, it was immersed in a 250° C. solder bath for 10 seconds. Thereafter, PCT was performed in saturated steam at 127° C. and 2.5 atm, and disconnections due to aluminum corrosion were evaluated as defects.

[Effects of the Invention] As is clear from the above explanation and Table 1, the soil-retaining resin composition of the present invention has good adhesion to semiconductor chips and lead frames, is less affected by moisture absorption, and can be used in solder baths. It has excellent moisture resistance even after being immersed in water, and as a result, it is possible to significantly reduce the occurrence of disconnection due to electrode corrosion and leakage current due to moisture, and moreover, it is possible to guarantee unicondylarity for a long time. Furthermore, it exhibited poor solder heat resistance despite being immersed in a solder bath at 250°C.

Claims (1)

[Claims] 1. (A) an epoxy resin, (B) a novolac type phenol resin, (C) a fluorine-substituted alkyl alkoxysilane compound, and (D) an inorganic filler as essential components, with respect to the entire resin composition. , the above (C
) of the fluorine-substituted alkyl alkoxysilane compound.
1 to 5% by weight, and 25 to 5% of the inorganic filler (D) above.
A sealing resin composition characterized in that it contains 90% by weight. 2 Claims in which the equivalent ratio [(a)/(b)] between the epoxy group (a) of the epoxy resin and the phenolic hydroxyl group (b) of the novolac type phenol resin is within the range of 0.1 to 10. The sealing resin composition according to item 1.